Experimental analysis of zero-gap laser welding of zinccoated steels in a lap joint configuration. (May 2020)

• Record Type: Journal Article
• Authors: Franz, Alexander; Paethe, Dieter; Dilger, Klaus
• Is Part Of: Proceedings of the Institution of Mechanical Engineers. Volume 234:Number 5(2020)
• Page Start: 658
• Page End: 664
• Publication Date: 2020-05
• Subjects: Keyhole stability -- laser beam welding -- process stability -- zero gap lap joint configuration -- zinc-coated steels; Materials -- Periodicals; Engineering design -- Periodicals; 620.11
• DOI: 10.1177/1464420720903754
• Languages: English
• ISSNs: 1464-4207

Abstract

Automotive manufacturing requires high productive manufacturing technologies to ensure a high-volume efficient production. Joining metal sheets in an overlap joint configuration of zinc-coated steel is an important task for body-in-white production. This paper describes the influence of different spot sizes regarding process stability in laser beam welding. Therefore, welds were performed in an overlap joint configuration with fully penetrated welds. Relevant material combinations for automotive industry were investigated. A broad-based parameter study and the analysis of interaction between spot- and keyhole diameter state a higher process stability. Welds with a smaller spot diameter lead to a sufficient increase of joint quality by using a zero gap overlap configuration. It is shown that the amount of joint instabilities such as pores, pinholes, spatter and further defects can be minimized by using smaller spot diameters. This can be explained by different keyhole regimes. Moreover, the change of isothermal interaction in the interlayer zone caused by the adjusted spot diameter leads to high-quality joints.